Velocipede-gear



O. S. MoINTIRE. VELOGIPEDE GEAR.

Patented Sept. 8, 1896.

5: a g u %ZMM Same/1m NITED STATES ATENT rrrcn.

CHARLES S. MCINTIRE, OF ALLEGHENY, PENNSYLVANIA, ASSIGNOR TO THE U. S.CYCLE IMPROVEMENT COMPANY, OF PITTSBURG, PENNSYLVANIA.

VELOCIPEDE-GEAR.

SPECIFICATION forming part of Letters Patent No. 567,155, datedSeptember 8, 1896.

Application filed rarel 7, 1896. Serial No. 578,442. (No model.)

T0 aZZ whom it may concern:

Be it known that I, CHARLES S. MoINTIRE, a citizen of the United States,residing at Allegheny, in the county of Allegheny and State ofPennsylvania, have invented or discovered new and useful Improvements inVelocipede-Gear, of which the following is a specification.

In the accompanying drawings,which make part of this specification,Figure 1 is a side elevation of my improvement, and Fig. 2 is a planwith wheel in horizontal section.

My improvements, generally stated, relate to a compound drivingear forvelocipedes, wherein power is transmitted from the pedalshaft to theshaft of the driving-wheel, pri marily, by sprocket and wheels and ashort chain, and, secondarily, by crank-s and connecting-rods.

It is well known that various styles of driving-gear have been inventedto span the distance between the pedal-shaft and the shaft of thedriving-wheel.

From all the mechanism proposed the trade has almost universally adoptedthe sprocket wheels and chain, not because it is satisfactory, but theleast objectionable. The ordinary length of this sprocket-chain isfifty-two inches, and among other defects may be enumerated its tendencyto stretch, to bind against the points of the sprocket-teeth, and toslip. It also presents a large number of pockets well adapted to receivedust, oil, and mud, and the same fact is true of the sprocketwheel.Every wheelman knows the injury caused in this way by cutting the teethof the wheel. There is always also some backlash. chain has not thus farbeen altogether satisfactory and apparently never will be owing toinherent difficulties, which will be ever present. One of thesedifficulties is backlash, since there are from three to nine gear-wheelsused, and there must be sufficient space between each pair to permit theteeth to enter and clear themselves.

Another serious question in the ordinary cogged-gear-driven machine isthat of alinement, for if the frame is warped or twisted the teeth willobviously not mesh, and to se- The attempt to substitute gears for thecure permanent rigidity of frame requires a comparatively heavystructure. For this reason it is neither mechanically nor practicallyfeasible to use ball-bearin gs on the usual train of gear-wheels. Theconditions, therefore, seem' to require a chain despiteitsdisadvantages.

In the construction set forth in this specification I use, it is true, achain, but its length is only one-fourth that of the ordinary chain, asit only covers. a portion of the distance between the pedal-shaft andthe shaft of the driving-wheel, and for this reason its stretch isreduced to one-fourth. The chain also is protected from dirt and mud andthe sprocketwheels are set so close together that slipping ispractically overcome.

The chain portion of the driving-gear covers only preferably aboutone-fifth of the distance between the pedal and driving-wheel shafts.The remaining four-fifths is covered by rigid connecting-rods, as willbe more clearly seen in the detailed description. The result is that thechain is so short that the whole driving-gear is practically a rigid oneand possesses all the desirable features of such a connection.

In the several views, 2 is a gear-case, of any appropriate form,preferably filled with lubricant and secured between the bottom tube A,upright tube B, and bottom stays of the frame.

In suitable bearings in the side walls turns pedal-shaft 3.

4 4 are the pedal-cranks.

5 is a sprocket-wheel keyed on shaft 3, but preferably only three inchesin diameter.

6 is a second sprocket, preferably one and three-eighths inches indiameter and about three inches behind the first sprocket-wheel. It issecured to counter-shaft 7, which also has bearings in the side walls ofthe case 2.

8 is a sprocket-chain connecting the two wheels, and for the sizes juststated would be thirteen inches long. Upon the opposite ends ofcounter-shaft 7, which project through the case, are hung two cranks 99, connected to connecting-rods 1O 10, which at their rear ends areprovided with cranks 11 11, fast upon the shaft 12 of the reardriving-wheel 13. The cranks 9 9 and 11 11 are desirably set at an angleof ninety degrees to their mates.

It will also be seen that when the pedalshaft is at the point where therider can use the least muscular power the crank on the counter-shaft 6is at its position for exerting the most power mechanically.

N o dead-centers are possible, for it is only once in nine revolutionsthat the angle of the pedal-cranks is the same as the angle with one ofthe cranks 9 9 on the counter-shaft, and then onlywith one, never withtwo simultaneously.

The proportions of the machine above given may be Varied, but I believeonly to disadvantage. One important fact is that the only Invelocipedes, the GOIIllJillHlllOllO'f afranic; a case secured to thelower ends of the bot tom tube and upright tube; a pedal-shaft journaledin the forward end of said case substantially at the point ofintersection of the prolongation of the bottom and upright tubes; asprocket-wheel upon said pedal-shaft; a countenshaft journaled in saidcase immediately in the rear of the pedal-shaft; a reduced sprocket-wheel upon said countershaft; a chain connecting the twosprocketwheels; cranks upon the ends of the countershaft; a reardriving-wheel; cranks upon the axle of said driving-wheel and paralleldriving-rods connecting the pairs of cranks.

In testimony whereof I have hereunto set my hand this 1st day ofFebruary, A. D. 1896.

CHARLES S. MGINIIRE. Witnesses:

WM. L. PIERCE, L. D. IAMs.

